I have rented through various agencies in London and am now generally suspicous around a) things getting sorted before moving in, but after contracts have been signed and b) the general service during the tenure.
There were a couple of bits to do before we moved in and both were completed to a high standard on time. During our stay there we have had occasional contact with the agency who have always been very helpful professional and reliable. They have sorted out a couple of wear and tear issues and throughout have just been really really good. Recommend them very highly.